Privileging place: reflections on involving people with dementia in recidency

Although attention is paid to involving people with dementia as collaborators in research, the issue of place – where involvement actually occurs – has been neglected. This is significant because we know from the academic literature that places can adversely affect social relations and a person’s ability to participate as equal partners. This paper privileges place and documents our experiences of running residencies in the English Lake District with people with dementia – Houston, Gardiner and Wallace all have some form of dementia. In doing so we provide a model to reference for involving people with dementia in research and knowledge production, while simultaneously strengthening the evidence base for the residency as a method for participatory research. People with dementia participated in two residencies to co-produce a touring exhibition and educational resource as part of a research dissemination project. We found that by privileging place a more equitable, productive, healthier, and respectful way of involving people with dementia as collaborators in research dissemination could be realised. The project has wider implications for the involvement of people with dementia in not only research, but also public consultations, service evaluations, and policy-related work

Deconvoluting the Molecular Control of Binding and Signaling at the Amylin 3 Receptor: RAMP3 Alters Signal Propagation through Extracellular Loops of the Calcitonin Receptor

Amylin is coexpressed with insulin in pancreatic islet β-cells and has potent effects on gastric emptying and food intake. The effect of amylin on satiation has been postulated to involve AMY3 receptors (AMY3R) that are heteromers of the calcitonin receptor (CTR) and receptor activity-modifying protein 3 (RAMP3). Understanding the molecular control of signaling through the AMY3R is thus important for peptide drug targeting of this receptor. We have previously used alanine scanning mutagenesis to study the contribution of the extracellular surface of the CTR to binding and signaling initiated by calcitonin (CT) and related peptides (Dal Maso, E., et al. (2019) The molecular control of calcitonin receptor signaling. ACS Pharmacol. Transl. Sci.2, 31–51). That work revealed ligand- and pathway-specific effects of mutation, with extracellular loops (ECLs) 2 and 3 particularly important in the distinct propagation of signaling mediated by individual peptides. In the current study, we have used equivalent alanine scanning of ECL2 and ECL3 of the CTR in the context of coexpression with RAMP3 to form AMY3Rs, to examine functional affinity and efficacy of peptides in cAMP accumulation and extracellular signal-regulated kinase (ERK) phosphorylation (pERK). The effect of mutation was determined on representatives of the three major distinct classes of CT peptide, salmon CT (sCT), human CT (hCT), and porcine CT (pCT), as well as rat amylin (rAmy) or human α-CGRP (calcitonin gene-related peptide, hCGRP) whose potency is enhanced by RAMP interaction. We demonstrate that the dynamic nature of CTR ECL2 and ECL3 in propagation of signaling is fundamentally altered when complexed with RAMP3 to form the AMY3R, despite only having predicted direct interactions with ECL2. Moreover, the work shows that the role of these loops in receptor signaling is highly peptide dependent, illustrating that even subtle changes to peptide sequence may change signaling output downstream of the receptor

Genetically encoded photocross-linkers determine the biological binding site of exendin-4 peptide in the N-terminal domain of the intact human glucagon-like peptide-1 receptor (GLP-1R)

The glucagon-like peptide-1 receptor (GLP-1R) is a key therapeutic target in the management of type II diabetes mellitus, with actions including regulation of insulin biosynthesis and secretion, promotion of satiety, and preservation of β-cell mass. Like most class B G protein-coupled receptors (GPCRs), there is limited knowledge linking biological activity of the GLP-1R with the molecular structure of an intact, full-length, and functional receptor·ligand complex. In this study, we have utilized genetic code expansion to site-specifically incorporate the photoactive amino acid p-azido-l-phenylalanine (azF) into N-terminal residues of a full-length functional human GLP-1R in mammalian cells. UV-mediated photolysis of azF was then carried out to induce targeted photocross-linking to determine the proximity of the azido group in the mutant receptor with the peptide exendin-4. Cross-linking data were compared directly with the crystal structure of the isolated N-terminal extracellular domain of the GLP-1R in complex with exendin(9–39), revealing both similarities as well as distinct differences in the mode of interaction. Generation of a molecular model to accommodate the photocross-linking constraints highlights the potential influence of environmental conditions on the conformation of the receptor·peptide complex, including folding dynamics of the peptide and formation of dimeric and higher order oligomeric receptor multimers. These data demonstrate that crystal structures of isolated receptor regions may not give a complete reflection of peptide/receptor interactions and should be combined with additional experimental constraints to reveal peptide/receptor interactions occurring in the dynamic, native, and full-length receptor state

Extracellular loops 2 and 3 of the calcitonin receptor selectively modify agonist binding and efficacy.

Class B peptide hormone GPCRs are targets for the treatment of major chronic disease. Peptide ligands of these receptors display biased agonism and this may provide future therapeutic advantage. Recent active structures of the calcitonin (CT) and glucagon-like peptide-1 (GLP-1) receptors reveal distinct engagement of peptides with extracellular loops (ECLs) 2 and 3, and mutagenesis of the GLP-1R has implicated these loops in dynamics of receptor activation. In the current study, we have mutated ECLs 2 and 3 of the human CT receptor (CTR), to interrogate receptor expression, peptide affinity and efficacy. Integration of these data with insights from the CTR and GLP-1R active structures, revealed marked diversity in mechanisms of peptide engagement and receptor activation between the CTR and GLP-1R. While the CTR ECL2 played a key role in conformational propagation linked to Gs/cAMP signalling this was mechanistically distinct from that of GLP-1R ECL2. Moreover, ECL3 was a hotspot for distinct ligand- and pathway- specific effects, and this has implications for the future design of biased agonists of class B GPCRs

The Molecular Control of Calcitonin Receptor Signaling

The calcitonin receptor (CTR) is a class B G protein-coupled receptor (GPCR) that responds to the peptide hormone calcitonin (CT). CTs are clinically approved for the treatment of bone diseases. We previously reported a 4.1 Å structure of the activated CTR bound to salmon CT (sCT) and heterotrimeric Gs protein by cryo-electron microscopy (Liang, Y.-L., et al. Phase-plate cryo- EM structure of a class B GPCR-G protein complex. Nature 2017, 546, 118–123). In the current study, we have reprocessed the electron micrographs to yield a 3.3 Å map of the complex. This has allowed us to model extracellular loops (ECLs) 2 and 3, and the peptide N-terminus that previously could not be resolved. We have also performed alanine scanning mutagenesis of ECL1 and the upper segment of transmembrane helix 1 (TM1) and its extension into the receptor extracellular domain (TM1 stalk), with effects on peptide binding and function assessed by cAMP accumulation and ERK1/2 phosphorylation. These data were combined with previously published alanine scanning mutagenesis of ECL2 and ECL3 and the new structural information to provide a comprehensive 3D map of the molecular surface of the CTR that controls binding and signaling of distinct CT and related peptides. The work highlights distinctions in how different, related, class B receptors may be activated. The new mutational data on the TM1 stalk and ECL1 have also provided critical insights into the divergent control of cAMP versus pERK signaling and, collectively with previous mutagenesis data, offer evidence that the conformations linked to these different signaling pathways are, in many ways, mutually exclusive. This study furthers our understanding of the complex nature of signaling elicited by GPCRs and, in particular, that of the therapeutically important class B subfamily

Agnes & Nancy

Agnes &amp; Nancy is a short documentary film (24 mins) inspired by original research on dementia activism undertaken by Dr Ruth Bartlett (2008-2010). The film captures the friendship that has grown between Agnes &amp; Nancy, two women with dementia, who have got to know each other through their involvement in the Scottish Dementia Working Group – an independent campaign group set up and run by people with dementia. Agnes and Nancy both have dementia and live independent lives. The film gently unfolds as Agnes journeys to Nancy’s home in rural Scotland for the first time, and ends with Agnes back at home again, reflecting on her ‘journey to the new Agnes’. <br/

Privileging place: reflections on involving people with dementia in a residency

Although attention is paid to involving people with dementia as collaborators in research, the issue of place – where involvement actually occurs – has been neglected.This is significant because we know from the academic literature that places can adversely affect social relations and a person’s ability to participate as equal partners. This paper privileges place and documents our experiences of running residencies in the English Lake District with people with dementia – Houston, Gardiner and Wallace all have some form of dementia. In doing so we provide a model to reference for involving people with dementia in research and knowledge production, while simultaneously strengthening the evidence base for the residency as method for participatory research. People with dementia participated in two residencies to co-produce a touring exhibition and educational resource as part of a research dissemination project.We found that by privileging place a more equitable, productive, healthier, and respectful way of involving people with dementia as collaborators in research dissemination could be realised. The project has wider implications for the involvement of people with dementia in not only research, but also public consultations, service evaluations, and policy-related work

Privileging place: reflections on involving people with dementia in recidency

Although attention is paid to involving people with dementia as collaborators in research, the issue of place – where involvement actually occurs – has been neglected. This is significant because we know from the academic literature that places can adversely affect social relations and a person’s ability to participate as equal partners. This paper privileges place and documents our experiences of running residencies in the English Lake District with people with dementia – Houston, Gardiner and Wallace all have some form of dementia. In doing so we provide a model to reference for involving people with dementia in research and knowledge production, while simultaneously strengthening the evidence base for the residency as a method for participatory research. People with dementia participated in two residencies to co-produce a touring exhibition and educational resource as part of a research dissemination project. We found that by privileging place a more equitable, productive, healthier, and respectful way of involving people with dementia as collaborators in research dissemination could be realised. The project has wider implications for the involvement of people with dementia in not only research, but also public consultations, service evaluations, and policy-related work

High-Throughput Screening to Identify Inhibitors of <i>Plasmodium falciparum</i> Importin α

The global burden of malaria and toxoplasmosis has been limited by the use of efficacious anti-parasitic agents, however, emerging resistance in Plasmodium species and Toxoplasma gondii threatens disease control worldwide, implying that new agents/therapeutic targets are urgently needed. Nuclear localization signal (NLS)-dependent transport into the nucleus, mediated by members of the importin (IMP) superfamily of nuclear transporters, has shown potential as a target for intervention to limit viral infection. Here, we show for the first time that IMPα from P. falciparum and T. gondii have promise as targets for small molecule inhibitors. We use high-throughput screening to identify agents able to inhibit P. falciparum IMPα binding to a P. falciparum NLS, identifying a number of compounds that inhibit binding in the µM-nM range, through direct binding to P. falciparum IMPα, as shown in thermostability assays. Of these, BAY 11-7085 is shown to be a specific inhibitor of P. falciparum IMPα-NLS recognition. Importantly, a number of the inhibitors limited growth by both P. falciparum and T. gondii. The results strengthen the hypothesis that apicomplexan IMPα proteins have potential as therapeutic targets to aid in identifying novel agents for two important, yet neglected, parasitic diseases